It is intended to provide a lipase activity inhibitor which shows a high inhibitory activity on pancreatic lipase, regulates the absorption of fat from meals and/or contributes to the regulation or prevention of obesity, a food and a drink containing the same, and a tea-origin lipase inhibitor being highly preferable and not worsening taste. It is also intended to provide a method of producing the lipase inhibitor. It is further intended to provide antioxidative agent. To overcome these problems, an epigallocatechin dimer (oolong homo bis flavans) or trimer is added to foods or drinks. Thus, the absorption of fat from meals can be regulated and an antioxidative effect can be obtained. The above compounds can be produced by reacting epigallocatechin gallate with formaldehyde in the presence of an acid.